Display devices are used in a variety of applications. For example, thin film transistor liquid crystal displays (TFT-LCDs) are used in, among other things, notebook computers, flat panel desktop monitors, LCD televisions, and a variety of communication devices.
Many display devices, such as TFT-LCD panels and organic light-emitting diode (OLED) panels, are made directly on flat glass sheets (glass substrates). To increase production rates and reduce costs, a typical panel manufacturing process simultaneously produces multiple panels on a single substrate.
To take advantage of economics of scale, display manufacturers require ever larger substrates so that more displays and/or larger displays can be manufactured on an individual substrate. The production of larger substrates has proved challenging to the glass manufacturing industry, especially in view of the fact that the substrate thickness is typically less than a millimeter, e.g., 0.7 millimeters. Particularly challenging has been the problem of managing the behavior of molten glass on the forming apparatus (e.g., isopipe) used to produce the substrate.
The present disclosure addresses this problem and, among other things, provides methods and apparatus for thermally conditioning the molten glass before it reaches the forming apparatus so as to improve the glass' mass, thickness, and/or temperature distribution on the surface of the forming apparatus.